JPS61265320A - Engine cooling device for vehicle - Google Patents

Abstract

PURPOSE:To enable to always perform optimum cooling through simple structure and with easiness of maintenance and inspection, by a method wherein a motor- operated pump, mounted in a cooling water passage, is driven in an optimum condition according to a cooling water temperature and an operating condition. CONSTITUTION:A motor-operated pump 9 is mounted to the discharge side of a radiator 2, and through control of driving of a driving motor M for the pump by means of a control unit 10, cooling water is circulated within an enclosed passage containing a water jacket 1 and the radiator 2. The control unit 10 drives and controls the motor-operated pump 9 by means of detecting signals from water temperature sensors S1, S2, an oil temperature sensor S3, an intake air temperature sensor S4, a rotation sensor S5, a gear position sensor S6, a car speed sensor S7, which respectively detect a cooling water temperature, and the operating conditions of an engine, and according to a program set depending upon the ON and the OFF states of an ignition switch IG-SW and an air conditioner switch AC-SW.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a water-cooled vehicle engine cooling device for a vehicle engine such as an automobile.

Traditionally, in this type of vehicle engine cooling system, cooling water is pumped into a sealed passage that includes a water jacket 1 and a radiator 2 of the engine using a water pump 3, as shown in FIG. I'm trying to force the circulation by letting it go.

In addition, a thermostat 4 is installed at the position shown in the figure to open and close the cooling channel opening/closing valve as appropriate depending on the water temperature, so that the cooling water with a low water temperature can be brought up to an appropriate temperature in a short time immediately after the engine starts. I have to. Note that the water pump 3 is configured to obtain driving force from the output shaft of the crankshaft 5 of the engine via a belt/pulley mechanism. In the figure, 6 is the pulley on the engine output shaft side, 7
is the pulley on the water pump drive shaft side, 8 is the pulley 6.7
Each shows a belt stretched between them.

However, in such a conventional vehicle engine cooling system, the water pump 3 is directly driven by the engine output, so its driving force depends on the engine speed, and the amount of coolant discharged varies. control range is narrow. In addition, in response to fluctuations in cooling water temperature, the amount of cooling water for the engine is adjusted by controlling the opening and closing of the cooling water channel using the thermostat 4, but normally the temperature control range is 65 to 75 degrees Celsius when the valve begins to open.
The full opening temperature is narrow at around 80 to 85 degrees Celsius. Further, when the engine is stopped, the water pump 3 does not work at all, and if the engine is suddenly stopped after driving for a long time, the temperature of the engine becomes abnormally high.

Therefore, even the combination of the water pump 3 and the thermostat 4 is not sufficient to maintain the engine temperature at the optimum level, and depending on the operating conditions of the engine, the engine may not be cooled sufficiently, resulting in overheating or overcooling of the engine. This means that there is a risk of overcooling.

If the engine cooling efficiency is poor, not only will fuel efficiency be reduced, but also component reliability will be reduced due to thermal history issues.

Furthermore, since the water pump 3 is provided within the water jacket 1 of the engine and the thermostat 4 is provided within a sealed cooling waterway, it is not easy to install them, and maintenance and inspection are difficult. Therefore, it is necessary to use water pumps 3 and thermostats 4 with sufficient durability in mind.The present invention has been made in consideration of the above points.

To provide an engine cooling device for a vehicle that has a simple structure and is easy to maintain and inspect, and can always optimally cool an engine according to the operating state of the engine.

In order to achieve the object, the present invention provides an electric pump for circulating cooling water in the cooling water channel of the engine, and a control unit operates the electric pump according to the output signals of various sensors that detect the temperature of the cooling water and the operating state of the engine. The pump is driven optimally.

Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

In the vehicle engine cooling device according to the present invention, the first
As shown in the figure, when circulating cooling water in a sealed passage that includes the water jacket 1 and radiator 2 of the engine,
An electric pump 9 for circulating cooling water is attached to the discharge side of the radiator 2, and a drive motor M of the pump 9 is controlled by a control unit (ECU) 10.

The control unit 10 performs optimal cooling water circulation according to the current cooling water temperature and engine operating state based on detection signals from various sensors that respectively detect the cooling water temperature and engine operating state. The motor M of the electric pump 9 is driven and controlled using a preset program so that the operation can be performed.

Here, in the control unit 10, each detection signal of the water temperature sensors Sl and S2, which respectively detect the temperature of the cooling water in the radiator 2 and the temperature of the cooling water in the water jacket 1 of the engine, and the temperature of the lubricating oil in the engine are detected. Detects the temperature state of the engine based on the detection signal of the oil temperature sensor S3, which detects the intake air temperature of the engine, and the detection signal of the rotation sensor S5, which detects the engine rotation speed, and the detection signal of the rotation sensor S5, which detects the engine speed. The operating state of the engine (including the degree of load on the engine) can be detected based on the detection signal of the gear position sensor S6, which detects the gear shift position, and the detection signal of the vehicle speed sensor S7', which detects the vehicle speed. I have to.

In the figure, 11 indicates a gear case.

Also, in the control unit 10, the engine ignition switch IG-SW is turned on.

By detecting the off state, you can know whether the engine is running or stopped, and also check the near conditioner switch A.
By detecting whether the C-SW is on or off, it is possible to know whether a particularly large load is being applied to the engine.

However, in a device configured in this way, the detection signals of various sensors S1 to S7 that respectively detect the temperature of the cooling water and the operating state of the engine, the ignition switch IG-5W and the air conditioner switch AC
A program for controlling the drive of the electric pump 9 according to the on/off state of -8W is set, for example, as follows.

1. The detection signal of the water temperature sensor S2 indicates that the cooling water temperature in the water jacket 1 is at a high level H, and the detection signals of the oil temperature sensor S3 and intake temperature sensor S4 indicate that the oil temperature and intake temperature are both at the H level. ignition switch IG-5W and near conditioner switch AC-3W are both in the on state, gear position sensor S6 is in the overdrive OD position,
The rotation sensor S5 indicates that the engine rotation speed is at a high level H level (or the engine rotation speed is constant), and the vehicle speed sensor S7 indicates that the vehicle is traveling at a high level with a large load on the engine. If it is detected that the engine is running, the drive motor M of the electric pump 9 is continuously rotated at the maximum rotation speed to maximize engine cooling efficiency. At this time, it is detected from the detection signal of the water temperature sensor S1 that the temperature of the cooling water in the radiator 2 is at a relatively low L level. However, in this case, overheating of the engine is effectively prevented and fuel efficiency is improved.

2. The detection signals from the water temperature sensors Sl and S2 indicate that the coolant temperature in the radiator 2 and water jacket 1 is at a high level H, and the detection signal from the oil temperature sensor S3 indicates that the oil temperature is at the H level and the engine temperature is low. The intake temperature sensor S4 detects that the intake temperature is at the low L level, and the ignition switch IG-
3W is off and gear position sensor S6 is parking P
If it is detected that the vehicle is in the parked position, the drive motor M of the electric pump 9 is held rotating for a preset time by a timer in order to continue cooling the engine for a while. . Thereby, for example, when the engine is stopped after driving for a long time, it is possible to effectively prevent an increase in engine temperature, thereby improving the reliability of parts against thermal history.

In this case, after the engine is stopped, the temperature peak of the cooling water in the radiator 2 may be detected by the water temperature sensor S1, and the motor M of the electric pump 9 may be driven until the temperature peak falls to a predetermined value.

3. The detection signals of the water temperature sensors Sl and S2 indicate that the coolant temperature in the radiator 2 and water jacket 1 are both at the low L level, and the detection signal of the oil temperature sensor S3 indicates that the oil temperature is at the L level and the engine temperature is The detection signal from the intake temperature sensor S4 detects that the intake temperature is at the low L level, and the ignition switch IG-8W is on and the gear position sensor S
6 is in the neutral N position and the vehicle is stopped, and at that time, the near conditioner switch AC-3W is off and the engine speed is at a low L level based on the detection signal of the rotation sensor S5. In this case, the drive motor M of the electric pump 9 is stopped. As a result, overcooling of the engine is prevented and fuel efficiency can be effectively improved.

4. The detection signals from the water temperature sensors Sl and S2 indicate that the coolant temperature in the radiator 2 and water jacket 1 are both at the low L level, and the detection signal from the oil temperature sensor S3 indicates that the oil temperature is at the L level and the engine temperature is low. The intake temperature is in a low state, and the detection signal of the intake temperature sensor S4 indicates that the intake temperature is at the low L level, and the ignition switch IG-3W is off and the gear position sensor S
6 is at the parking P position and it is detected that the vehicle is in the parked state, the drive motor M of the electric pump 9 is periodically driven for a certain period of time.

This prevents the cooling water from freezing and maintains the water temperature, making it possible to prepare for starting the engine.

5. The detection signal from the water temperature sensor S1 indicates that the coolant temperature in the radiator 2 is at a low L level, and the detection signal from the water temperature sensor S2 indicates that the coolant temperature in the water jacket 1 is at a high H level. The detection signal of S3 indicates that the oil temperature is at H level and the engine temperature is high, and the detection signal of intake temperature sensor S4 indicates that the intake temperature is at a low level of L, and the ignition switch IG-3W is turned on. Gear position sensor S6 when on
is in the overdrive OD position, the near conditioner switch AC-8W is off, the engine speed is at a low level L according to the detection signal of the rotation sensor S5, and the traveling speed is at the H level according to the detection signal of the vehicle speed sensor S7. If it is detected that the vehicle is traveling at high speed without a large load being applied to the engine, the drive motor M of the electric pump 9 is driven to rotate under the control of a preset low speed duty. Thereby.

It becomes possible to maintain the engine temperature optimally and effectively improve fuel efficiency.

6. The cooling water temperature in the radiator 2 changes from L to H level according to the detection signal of the water temperature sensor S1, and the water temperature sensor S2
The detection signal causes the coolant temperature in the water jacket 1 to change from the L level to the H level, and the detection signal from the oil temperature sensor S3 causes the oil temperature to change from the L level to the H level, changing the engine temperature from low to high. Instead, the intake temperature changes from L to H level based on the detection signal of intake temperature sensor S4, ignition switch IG-8W is on, gear position sensor S6 is in drive D position, and near conditioner switch AC-8W is off. If the engine rotation speed and vehicle speed are kept constant based on the detection signals of the rotation sensor S5 and the vehicle speed sensor S7, the drive motor M of the electric pump 9 is controlled at a preset high-speed duty. Rotate it at the bottom. This makes it possible to maintain the engine temperature optimally and effectively improve fuel efficiency.

7. According to the detection signals of the water temperature sensors St and S2, the temperature of the cooling water in the radiator 2 and the water jacket is at the M level, which is the appropriate temperature, and the temperature of the cooling water in the radiator 2 and the water jacket is at the M level, which is the appropriate temperature, according to the detection signal of the oil temperature sensor S3, and the intake air temperature is The detection signal from the sensor S4 indicates that the intake air temperature is at the appropriate M level and the engine temperature is at the appropriate temperature, the ignition switch IG-8W is on, the gear position sensor S6 is in the overdrive ○D position, and When the near conditioner switch AC-5W is off and the engine rotation speed and vehicle speed are both kept constant based on the detection signals of the rotation sensor S5 and the vehicle speed sensor S7, the drive motor M of the electric pump 9 is stopped. . Thereby,
It becomes possible to maintain the engine temperature optimally and effectively improve fuel efficiency.

As described above, in the vehicle engine cooling device according to the present invention,
Since the pump that circulates the cooling water is electric, it does not cause any friction loss to the engine, and the electric pump can be simply installed at an appropriate location in the cooling waterway between the engine's water jacket and the radiator. This makes it easy to install and to perform maintenance and inspection. Furthermore, unlike conventional water pumps, there is no need to attach it to the engine, making it possible to effectively downsize the engine. In addition, the drive of the motor in the electric pump is controlled by a control unit that responds to the output signals of various sensors (including switches) that detect the temperature of the cooling water and the operating status of the engine, so that the temperature of the engine or its cooling water is always optimal. This is done with predictive ability to prevent the engine from overcooling or overcooling, effectively improving fuel efficiency, and preventing deterioration in reliability of parts due to thermal history. Become.

It goes without saying that the present invention can be applied not only to engine cooling, but also to all cooling systems that use cooling water. For example, the cooling device according to the present invention can be used as is in turbochargers, intercoolers, and the like.

As described above, in the vehicle engine cooling device according to the present invention, an electric pump for circulating cooling water is provided in the cooling water channel of the engine, and the output signals of various sensors that detect the temperature of the cooling water and the operating state of the engine are The control unit allows the electric pump to be driven optimally according to the engine operating conditions.It has a simple structure and is easy to maintain and inspect, and can always perform optimal engine cooling according to the engine operating condition. It has the great advantage of being able to

[Brief explanation of the drawing]

FIG. 1 is a simplified configuration diagram showing one embodiment of a vehicle engine cooling device according to the present invention, and FIG. 2 is a simplified configuration diagram showing a conventional vehicle engine cooling device. 1...Water jacket 2...Radiator 3
...Water pump 4...Thermostat 9.
...Electric pump 10...Control unit S
l, S2...Water temperature sensor S3...Oil temperature sensor S
4... Intake temperature sensor S5... Rotation sensor S6
...Gear position sensor S7...Vehicle speed sensor
IG-8W...Ignition switch AC-8W
...Near conditioner switch

Claims (1)

[Claims] In devices that forcefully circulate cooling water using a pump in a sealed passage that includes the water jacket and radiator of the engine, the pump is driven by a motor, and various sensors are installed to detect the temperature of the cooling water and the operating status of the engine. 1. A vehicle engine cooling device, characterized in that a control unit controls the drive of the motor according to an output signal.